This invention relates to a meta-search technique with which a search engine is discriminately used according to a request of a user, and more particularly, to a technique of retrieving a search engine that meets a request of a user.
As a result of prevalence of personal computers and the Internet, an amount of electronic documents that can be accessed by a user is increasing. As a countermeasure for such situation, there is known a document search technique. The document search technique is a technique of retrieving a document that matches a search query input by the user. It should be noted that the search query may be a keyword or a sentence.
A large number of search engines have been constructed on intranets of companies and the like, and on the Internet. The user uses those search engines to acquire an appropriate document. It should be noted that the search engines are classified into a general-purpose search engine, that is the horizontal search engine, and a dedicated-purpose search engine, that is the vertical search engine.
The general-purpose search engine searches large variety of document stored in the search engine. An example of the general-purpose search engine is Google™.
The vertical search engine retrieves the document requested by the user from among the specific types of documents. Examples of the vertical search engine include a patent search engine, a search engine for in-company reports, and a manual search engine.
The user needs to discriminately use an appropriate search engine to acquire an appropriate document. However, it is extremely complicated for the user to discriminately use the search engine according to a purpose of the search.
JP 2002-278980 A discloses a meta-search technique that solves the problem described above. The meta-search technique is a technique of integrally performing search processing with respect to a plurality of search engines. The specific processing is as follows. First, a search query is input to a meta-search engine. Then, the meta-search engine transmits a search request to the plurality of search engines in parallel. After that, the meta-search engine collectively outputs search results received from the respective search engines. As described above, the meta-search technique improves convenience of the user.
On the other hand, a quality of the search result is important for improving the convenience of the user. JP 2005-242760 A discloses a technique for improving a search quality. In the technique disclosed in JP 2005-242760 A, a search know-how of other users is used. Specifically, judgment is made on a value of a document corresponding to a search result, based on an operation of the user with respect to the search result.
Alternatively, “Information Retrieval Algorithm” by Kenji Kita, Kazuhiko Tsuda, and Masami Shishibori, KYORITSU SHUPPAN CO., LTD discloses various techniques for retrieving a document, such as a search using a Boolean expression, which includes an OR search, and a similarity search using a vector model.